It regulates the activity of the immune system, which may be overactive in some conditions. Hydroxychloroquine can modify the underlying disease process, rather than simply treating the symptoms. Chloroquine dosage for malaria prevention Eye exams for plaquenil Plaquenil can damage the retina of the eye, which can lead to blindness. This eMedTV page lists other side effects or complications that may occur with Plaquenil. Warnings and precautions on who should not use this drug are also listed on this page. PLAQUENIL prolongs the QT interval. Ventricular arrhythmias and torsades de pointes have been reported in patients taking PLAQUENIL see OVERDOSAGE. Therefore, PLAQUENIL should not be administered with other drugs that have the potential to prolong the QT interval see DRUG INTERACTIONS. Worsening Of Psorias Is And Porphyria Find patient medical information for Plaquenil Oral on WebMD including its uses, side effects and safety, interactions, pictures, warnings and user ratings. Hydroxychloroquine is often taken in combination with other drugs such as methotrexate. Over the long term hydroxychloroquine can reduce pain, swelling and joint stiffness. It may be as long as 12 weeks before you notice the benefits. Should users of hydroxychloroquine take cholesterol-lowering medications Medicines for the Prevention of Malaria While Traveling., Plaquenil Hydroxychloroquine Uses, Dosage, Side Effects. Plaquenil and accutane Hydroxychloroquine use in children younger than 7 may be limited by the difficulty in obtaining satisfactory evaluation of color vision in this age group. Therefore, children taking HCQ should receive an annual ophthalmologic examination. Other rare side effects include changes in skin pigmentation and cardiomyopathy diseases of the heart muscle. Drug spotlight on hydroxychloroquine Lupus Foundation of.. Plaquenil Oral Uses, Side Effects, Interactions.. Be Aware of These Statin Drug Interactions. Other Interactions. Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco. If you are also taking a certain drug for diarrhea kaolin or taking antacids such as magnesium /aluminum hydroxide, take hydroxychloroquine at least 4 hours before or after these products. These products may bind with hydroxychloroquine, preventing your body from fully absorbing it. Use this medication. How should I take hydroxychloroquine? Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended. Hydroxychloroquine is sometimes given only once per week. Choose the same day each week to take this medicine if you are on a weekly dosing schedule.